Drum-type washing machine

ABSTRACT

A drum-type washing machine includes left and right side plates formed of steel plates, the side plates defining side surfaces of an outer case, a front cover provided with an openable and closable door, the front cover defining a front surface of the outer case, an upper cover defining an upper surface of the outer case, a water tank oscillatably arranged in the outer case, and a rotary drum axially supported in the water tank, wherein a plurality of concave portions are formed on the left and right side plates, and the concave portion closer to the front surface of the outer case as a door side has an arc shape with a larger curvature. Thus, rigidity of the side plates in the up and down direction and the left and right direction is increased, so that vibration at the time of spin-drying is reduced.

TECHNICAL FIELD

The present invention relates to a configuration of a side surface of anouter case of a drum-type washing machine.

BACKGROUND ART

Conventionally, regarding a configuration of a side surface of an outercase of a drum-type washing machine, formation of a plurality of concaveportions extending in the horizontal direction in a thin steel plateserving as the side surface of the outer case by press working or thelike is proposed in order to reduce vibration at the time of spin-dryingand the like (for example, refer to Patent Literature 1).

FIG. 4 is a perspective view of an outer appearance of a conventionaldrum-type washing machine described in Patent Literature 1. As shown inFIG. 4, an outer case 41 of the drum-type washing machine is asubstantially rectangular parallelepiped which is vertically elongated.The outer case 41 includes an upper surface decorative cover 30 definingan upper surface of the outer case 41, an operation panel 31 providedwith a display screen and the like, the operation panel 31 defining afront surface upper part of the outer case 41, a front surfacedecorative cover 33 provided with an openable and closable door 32 in acenter, the front surface decorative cover 33 defining a front surfacecenter part of the outer case 41, a front surface lower part cover 34defining a front surface lower part of the outer case 41, and a leg base35 provided with a leg portion 39 attached on the lower side, the legbase 35 defining a bottom surface of the outer case 41.

Side plates 36 defining left and right surfaces of the outer case 41 aremade of thin steel plates and have substantially rectangular shapeswhich are vertically elongated. The side plates 36 support the entireweight of the outer case 41 together with the leg base 35.

As shown in FIG. 4, grip portions 38 for carrying the drum-type washingmachine and a concave portion 40 to which a caution seal or the like isattached are formed on the side plate 36. On the entire surface of theside plate 36 excluding the grip portions 38 and the concave portion 40,a plurality of concave portions 37 whose longitudinal directions are thehorizontal direction are formed. In the side plate 36, an area of theconcave portions 37, that is, an area of a plastically deformed part islarger than an area of a part where no concave portion 37 are formed.Thereby, surface rigidity of the entire side plate 36 is improved. Aresonance frequency of the side plate 36 is increased so as to come awayfrom a vibration frequency at the time of spin-drying. Thus, vibrationof the outer case 41 is reduced.

The concave portions 37 are formed so as to extend in the horizontaldirection over the entire surface of the side plate 36. This is becausethe side plate 36 has a substantially rectangular shape which isvertically elongated, and a large number of concave portions 37 can beformed if size P set as vertical width of the concave portions 37 isfixed. By such arrangement, a large number of concave portions 37 areformed, so that the surface rigidity is improved.

-   Patent Literature 1: JP 2010-63893 A

DISCLOSURE OF THE INVENTION Problems To Be Solved By the Invention

However, in a case where a shape of the side plate 36 is close to aregular square, the vibration is largely transmitted to the side plate36 in any direction of the up and down direction and the front and reardirection. Meanwhile, even when the rigidity in the up and downdirection is improved, the rigidity in the front and rear direction isnot sufficiently improved with the above conventional configuration.Therefore, in a case where the shape of the side plate 36 is close to aregular square, the rigidity according to the above conventionalconfiguration (rigidity in the front and rear direction in particular)is not always sufficient. As a result, there is a problem that thevibration of the side plate 36 is increased and an abnormal sound isgenerated at the time of a spin-drying operation. Alternatively, thereis a problem that an opening and closing action of the door 32 on thefront surface of the outer case 41 (at the time of closing inparticular) reflects the side plate 36 so that the side plate 36 isvibrated and the abnormal sound is generated.

Since a drum-type washing machine has a large water-saving effect, ademand of the drum-type washing machine is increased in recent years. Inaccordance with this, the drum-type washing machine is required to havean increased capacity. In order to increase the capacity, a rotary drum11 is formed so as to be elongated along an axis of rotation of therotary drum 11 (i.e., formed in such a manner that depth of the rotarydrum 11 is large). In such a way, depth of the product itself isincreased in accordance with an increase in washable capacity ofclothing. Thus, a rectangular shape in which size in the verticaldirection and the lateral direction are close to each other, that is, arectangular shape close to a regular square is increased in recent yearsas a shape of a side plate 8.

The present invention is to solve the above conventional problems, andan object thereof is to provide a drum-type washing machine for reducinggeneration of vibration and an abnormal sound by having high rigiditynot only in the up and down direction but also in the front and reardirection.

Means To Solving the Issue

In order to solve the above conventional problems, a drum-type washingmachine of the present invention includes left and right side platesformed of steel plates, the side plates defining side surfaces of anouter case, a front cover provided with an openable and closable door,the front cover defining a front surface of the outer case, an uppercover defining an upper surface of the outer case, a water tankoscillatably arranged in the outer case, and a rotary drum axiallysupported in the water tank, wherein a plurality of concave portions areformed on the left and right side plates, and the concave portion closerto the front surface of the outer case as a door side has an arc shapewith a larger curvature.

Thereby, high rigidity both in the up and down direction and in thefront and rear direction is obtained, so that the generation of thevibration and the abnormal sound is reduced.

Effect of the Invention

With the drum-type washing machine of the present invention, highrigidity both in the up and down direction and in the front and reardirection is obtained, so that the generation of the vibration and theabnormal sound is reduced.

BRIEF DESCRIPTION OF THE DRAWINGS

These aspects and features of the present invention will become clearfrom the following description taken in conjunction with the preferredembodiments thereof with reference to the accompanying drawings, inwhich:

FIG. 1 is a perspective view of an outer appearance of a drum-typewashing machine in an embodiment of the present invention;

FIG. 2 is a vertically sectional view of the same drum-type washingmachine along the line A-A of FIG. 1;

FIG. 3 is a plan view of the same drum-type washing machine when seenfrom the side; and

FIG. 4 is a perspective view of an outer appearance of a conventionaldrum-type washing machine.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

In a first aspect of the invention, a drum-type washing machine of thepresent invention includes left and right side plates formed of steelplates, the side plates defining side surfaces of an outer case, a frontcover provided with an openable and closable door, the front coverdefining a front surface of the outer case, an upper cover defining anupper surface of the outer case, a water tank oscillatably arranged inthe outer case, and a rotary drum axially supported in the water tank,wherein a plurality of concave portions are formed on the left and rightside plates, and the concave portion closer to the front surface of theouter case as a door side has an arc shape with a larger curvature. Withsuch a configuration, high rigidity both in the up and down directionand in the front and rear direction is obtained, so that generation ofvibration and an abnormal sound is reduced.

In a second aspect of the invention, in the drum-type washing machine ofthe first aspect of the invention, the concave portion arranged in aclosest position to the front surface of the outer case as the door sidehas a substantially semicircular shape. With such a configuration, withrespect to vibration transmitted to the side plates from a vicinity ofthe door at the time of a spin-drying operation, stronger surfacerigidity is obtained by the substantially semicircular concave portion.Therefore, vibration transmission to the entire side plates is reduced,so that vibration of the entire product is suppressed. With respect toimpact transmitted to the side plates via the front cover at the time ofclosing the door from a released state with strong force, strong surfacerigidity of the substantially semicircular concave portion is obtainedas well as at the time of the spin-drying operation. Therefore, anacoustic echo of the entire side plates is reduced.

In a third aspect of the invention, the drum-type washing machine of thefirst or second aspect of the invention, further includes a suspensionhanging down the water tank in the outer case, a damper for dampingvibration of the water tank, and a door packing arranged between thewater tank and the front cover on the door side, wherein the water tankis supported by the suspension, the damper, and the door packing. Withsuch a configuration, surface rigidity of the side plates correspondingto actions of the water tank in all directions at the time of thespin-drying operation is ensured, so that low vibration and low noiseare achieved.

Before the description of the present invention proceeds, it is to benoted that like parts are designated by like reference numeralsthroughout the accompanying drawings. Hereinbelow, embodiments of thepresent invention will be described with reference to the accompanyingdrawings. It should be noted that the present invention is not limitedto this embodiment.

Embodiment

FIG. 1 is a perspective view of an outer appearance of a drum-typewashing machine in the embodiment of the present invention. FIG. 2 is avertically sectional view of the same drum-type washing machine alongthe line A-A of FIG. 1. FIG. 3 is a plan view of the same drum-typewashing machine when seen from the side.

In FIG. 1, an outer case 1 is a substantially rectangular parallelepipedwhich is close to a cube. The outer case 1 is provided with an uppersurface decorative cover (upper cover) 2 defining an upper surface ofthe outer case 1, an operation panel 3 provided with a display screenand the like, the operation panel 3 defining a front surface upper partof the outer case 1, a front surface decorative cover (front cover) 5provided with an openable and closable door 4 substantially in a center,the front cover 5 defining a front surface of the outer case 1, a frontsurface lower part cover 6 defining a front surface lower part of theouter case 1, and a leg portion 7 attached to a bottom surface of theouter case 1.

The outer case 1 is further provided with left and right side plates 8formed of thin steel plates and defining side surfaces of the outer case1. The side plates 8 have substantially rectangular shapes which areclose to a regular square. It should be noted that FIG. 1 only shows oneof the side plates 8. In the following description, the directionperpendicular to the front surface decorative cover 5 is defined as the“front and rear direction” (X direction shown in FIG. 1), the directionperpendicular to the side plates 8 is defined as the “left and rightdirection” (Y direction shown in FIG. 1), and the directionperpendicular to the upper surface decorative cover 2 is defined as the“up and down direction” (Z direction shown in FIG. 1).

As shown in FIG. 1, a plurality of concave portions 9 are formed on theside plate 8. When the outer case 1 is seen from the side (left andright direction), the concave portion 9 which is closer to the frontsurface of the outer case 1 on the door 4 side has an arc shape with alarger curvature. The concave portions 9 can be formed by pressing anddrawing the steel plates to be the side plates 8. By this drawing step,the concave portions 9 are plastically deformed. According to thedrum-type washing machine in the present embodiment, surface rigidity ofthe side plates 8 of the thin steel plates is improved by utilizing theconcave portions 9 formed on the side plates 8. Vibration and anabnormal sound of the side plates 8 at the time of a spin-dryingoperation are reduced, and further, an acoustic echo, vibration, and thelike of the side plates 8 at the time of closing the door 4 with strongforce are reduced. A shape and the like of the concave portions 9 willbe described later in detail.

Next, the vibration acting on the side plates 8 will be described withusing FIG. 2.

As shown in FIG. 2, the outer case 1 is provided with a rotary drum 11driven and rotated by a motor 10, and a water tank 12 oscillatablyarranged in the outer case 1. The rotary drum 11 is axially supported inthe water tank 12 in such a manner that the rotary drum 11 is rotatableabout an axis of rotation parallel to the X direction.

Between an upper part of the water tank 12 and the upper surfacedecorative cover 2, suspensions 13 are attached. The suspensions 13 hangdown the water tank 12 in the outer case 1. The water tank 12 isoscillatably suspended down and anti-vibration supported by thesuspensions 13 in the outer case 1. Between a lower part of the watertank 12 and an outer case bottom plate 15, dampers 14 are attached. Thedampers 14 damping-support the water tank 12 so as to damp vibration ofthe water tank 12.

Further, on the door 4 side of the water tank 12, a door packing 17 isarranged between the water tank 12 and the front surface decorativecover 5. The door packing 17 made from flexible material such as rubberis arranged so as to be brought into watertight contact with an indoorglass 16 when the door 4 is closed. By arranging the door packing 17 insuch a way, the water tank 12 is brought into a watertight state againstan exterior of the outer case 1 when the door 4 is closed. The watertank 12 is supported by the suspensions 13, the dampers 14, and the doorpacking 17.

For example, at the time of the spin-drying operation, the rotary drum11 is rotated at high speed. When the rotary drum 11 is rotated at highspeed, clothing 18 as a laundry is moved in various directions in therotary drum 11. By the movement of the clothing 18 in various directionsin such a way, impact is transmitted from the rotary drum 11 to thewater tank 12, and the water tank 12 is intricately moved and vibratedin the up and down direction, in the left and right direction, and inthe front and rear direction.

Further, the vibration of the water tank 12 is transmitted to the sideplates 8. Specifically, the vibration of the water tank 12 istransmitted from the suspensions 13 and the dampers 14 to the sideplates 8 (not shown in FIG. 2) via the upper surface decorative cover 2and the bottom plate 15. This vibration is mainly composed of a wavemotion in the up and down direction. Meanwhile, the vibration of thewater tank 12 is transmitted from the door packing 17 to the side plates8 (not shown in FIG. 2) via the front surface decorative cover 5. Thisvibration is mainly composed of a wave motion in the front and reardirection.

Therefore, rigidity of the side plates 8 is required to have surfacerigidity corresponding to the vibration mainly in the up and downdirection transmitted from the suspensions 13 and the dampers 14 to theside plates 8 via the upper surface decorative cover 2 and the bottomplate 15, the vibration mainly in the front and rear directiontransmitted from the door packing 17 to the side plates 8 via the frontsurface decorative cover 5 from the front side of the door 4 side, andthe impact in the front and rear direction at the time of opening andclosing the door.

In particular, in a case where the shape of the side plate 8 is arectangular shape in which size in the vertical direction and thelateral direction are close to each other, that is, a shape close to aregular square, high surface rigidity not only in the up and downdirection but also in the front and rear direction is required as therigidity of the side plates 8. In the present embodiment, the concaveportions 9 are provided in order to obtain such surface rigidity.

Next, the concave portions 9 provided in order to obtain the abovesurface rigidity will be described with using FIG. 3.

In FIG. 3, the concave portions 9 formed on the side plate 8 include aconcave portion 9 a placed at the closest position to the front surfaceof the outer case 1 on the door 4 side and having a substantiallysemicircular shape, a concave portion 9 b arranged at the close positionto the door 4 next to the concave portion 9 a and having a substantiallyarc shape with a large curvature, and concave portions 9 c, 9 d, 9 eeach having a substantially arc shape with a curvature successivelydecreased from the concave portion 9 b toward the rear side. The concaveportions 9 b, 9 c, 9 d, 9 e have substantially arc shapes extending froman upper end toward a lower end in the up and down direction whilecurving from the front side to the rear side of the outer case 1. Itshould be noted that the concave portions 9 are recessed from the outerside of the outer case 1 toward the inner side of the outer case 1.

The curvatures of the concave portions 9 are set by a catenary curve(catenary). As shown in FIG. 3, the shape of the concave portion 9 aarranged at the closest position to the door 4 (on the most front sidein the front and rear direction) is a substantially semicircular shape.Thus, surface rigidity in the vicinity of a center part on the door 4side of the side plate 8 is particularly improved. It should be notedthat although the shape of the concave portion 9 a is a substantiallysemicircular shape in the present embodiment, the shape is not limitedto a substantially semicircular shape but may be a substantiallysemielliptical shape, a substantially arc shape, or other shapes. The“substantially semicircular shape” includes a semicircular shape, andthe “substantially arc shape” includes an arc shape.

Meanwhile, the shape of the concave portion 9 e which is the mostdistant from the door 4 (positioned on the most rear side in the frontand rear direction) is a catenary curve of an arc shape with a smallcurvature close to a substantially vertical line. Ends B on the upperand lower sides and on the rear side of the concave portion 9 e areclose to upper and lower corner portions 19 of the side plate 8. Byforming the concave portions 9 in such a manner that the concave portion9 e has such a shape, an area of the concave portions 9 is increased asfar as possible.

It should be noted that in a case where thickness of the side plate 8 is0.6 mm, the surface rigidity of the side plate can be improved bysetting depth of the concave portions 9 to 2.0 to 4.0 mm. However, thedepth of the concave portions 9 is not limited to the above depth butcan be appropriately set in consideration with the thickness of the sideplate 8 and other design matters.

When the outer case 1 is seen from the side, centers in the up and downdirection of the concave portions 9 a, 9 b, 9 c, 9 d, 9 e are favorablyset on a center of the door 4 and on the axis of rotation of the rotarydrum 11.

Actions and operations of the washing machine formed as above will bedescribed below.

The side plates 8 according to the present invention have the pluralityof arc-shaped concave portions so as to correspond to the vibrationmainly in the up and down direction transmitted from the suspensions 13and the dampers 14 to the side plates 8 via the upper surface decorativecover 2 and the bottom plate 15, and the vibration mainly in the frontand rear direction transmitted from the door packing 17 to the sideplates 8 via the front surface decorative cover 5 from the front side ofthe door 4 side. With such a configuration of the side plates 8, acomplicated plane shape is formed by the concave portions 9 when seenfrom the side, differently from a configuration that uniform concaveportions extending in the vertical direction are formed and aconfiguration that uniform concave portions extending in the horizontaldirection are formed. Therefore, high surface rigidity both in the upand down direction and in the front and rear direction is obtained byvirtue of the side plates 8.

By arranging the substantially semicircular concave portion 9 a at theclosest position to the door 4 in the front and rear direction, strongsurface rigidity is obtained with respect to the vibration mainly in thefront and rear direction transmitted from the direction shown by anarrow C of FIG. 3 to the side plates 8 via the door packing 17 in thevicinity of the door 4 at the time of spin-drying in particular.Therefore, vibration transmission to the entire side plates 8 isreduced, so that vibration of the entire product is suppressed.

The impact transmitted to the left and right side plates 8 via the doorpacking 17 and the front surface decorative cover 5 at the time ofclosing the door 4 with strong force from a released state is eased byvirtue of the strong surface rigidity according to the substantiallysemicircular concave portion 9 a as well as at the time of thespin-drying operation. Therefore, the acoustic echo, the vibration, andthe like of the entire side plates 8 are reduced.

It is to be noted that, by properly combining the arbitrary embodimentsof the aforementioned various embodiments, the effects possessed by themcan be produced.

As described above, in the drum-type washing machine according to thepresent invention, the vibration of the outer case at the time ofspin-drying and the abnormal sound at the time of opening and closingthe door can be reduced by increasing the surface rigidity of the sideplates 8, in particular, the surface rigidity in the vicinity of thedoor 4 on the front surface. Therefore, the washing machine can beapplied to other products accompanied by vibration and provided with anopen/close door (such as a dehydrator and a clothes dryer).

Although the present invention has been fully described in connectionwith the preferred embodiment thereof with reference to the accompanyingdrawings, it is to be noted that various changes and modifications areapparent to those skilled in the art. Such changes and modifications areto be understood as included within the scope of the present inventionas defined by the appended claims unless they depart therefrom.

The entire disclosure of Japanese Patent Application No. 2011-030487filed on Feb. 16, 2011 including specification, drawings, and claims isincorporated herein by reference in its entirety.

DESCRIPTION OF REFERENCE SIGNS

1: OUTER CASE

2: UPPER SURFACE DECORATIVE COVER (UPPER COVER)

4: DOOR

5: FRONT SURFACE DECORATIVE COVER (FRONT COVER)

8: SIDE SURFACE PLATE

9: RECESSED PORTION

11: ROTARY DRUM

12: WATER TANK

13: SUSPENSION

14: DAMPER

17: DOOR PACKING

1. A drum-type washing machine, comprising: left and right side platesformed of steel plates, the side plates defining side surfaces of anouter case; a front cover provided with an openable and closable door,the front cover defining a front surface of the outer case; an uppercover defining an upper surface of the outer case; a water tankoscillatably arranged in the outer case; and a rotary drum axiallysupported in the water tank, wherein a plurality of concave portions areformed on the left and right side plates, and the concave portion closerto the front surface of the outer case as a door side has an arc shapewith a larger curvature.
 2. The drum-type washing machine according toclaim 1, wherein the concave portion arranged in a closest position tothe front surface of the outer case as the door side has a substantiallysemicircular shape.
 3. The drum-type washing machine according to claim1, further comprising a suspension hanging down the water tank in theouter case, a damper for damping vibration of the water tank, and a doorpacking arranged between the water tank and the front cover on the doorside, wherein the water tank is supported by the suspension, the damper,and the door packing.
 4. The drum-type washing machine according toclaim 2, further comprising a suspension hanging down the water tank inthe outer case, a damper for damping vibration of the water tank, and adoor packing arranged between the water tank and the front cover on thedoor side, wherein the water tank is supported by the suspension, thedamper, and the door packing.